Method and system for displaying content while reducing burn-in of a display

ABSTRACT

A method and system for reducing burn-in of a display is disclosed. A plurality of assets containing text, graphics, and video are stored and then gathered. These assets are then assembled into a template to form a video frame or “screen”, which is subsequently output in a video transport stream or video display. Based upon a trigger, the assets are gathered again and reassembled in a second template to form a second video frame or screen wherein the assets are in positions on the screen, which are different from those of the first screen. The second screen is subsequently output to the video transport stream and the process is repeated.

FIELD OF THE INVENTION

This invention is related to a method and system for displaying content while prolonging the life of a display by reducing phosphor burning on the display.

BACKGROUND OF THE INVENTION

Displays such as cathode ray tubes (CRTs) are well known for displaying motion pictures and other content such as graphical or textual content. A typical CRT has a screen that is coated on an inner surface with phosphorescent material arranged in a given pattern. The phosphorescent material glows when bombarded by electron beams emanating from electron guns to form a pattern corresponding to an image. In time, the glowing causes the phosphorescent material to wear, thus affecting its ability to display an image on the screen. It is desirable to have the phosphorescent material wear evenly across the entire screen so that over time the contrast and image display capabilities are uniform across the entire screen. Similar wear can occur with projection and plasma displays as well. It is equally desirable for these devices to exhibit even wear of the materials that facilitate their luminance.

In displays, for example, images move frequently as in a motion picture, thus allowing various parts of the phosphorescent material on the screen to glow at different times. This has an averaging effect on the wear characteristics such that no localized area of the phosphorescent material on the screen wears more or less than an adjacent localized area. However, in other instances, displayed images may contain various stationary content such as pictures, text, graphics or other stationary content. Additionally, as in the case of text, a sharp contrast may exist between the glowing areas of the text and the adjoining areas of the screen. The stationary aspect of the image, and especially the sharp contrast combined with the stationary aspect, causes uneven phosphorescent material wear characteristics between adjacent localized areas on the screen. Damage can result to the phosphorescent screen in these areas such that images are burned into the screen leaving an undesirable permanent scar in the phosphorescent coating. As a consequence, when further images are displayed in the scarred area, the outline of the image may be blurred or the outline of the scar may remain partially or totally visible. This effect is well known in the industry as screen burn-in.

In order to address this burn-in problem, various methods have been developed. For example, in computer applications where a CRT is used as a monitor, the computer generates various screen savers which turn off the still text and replace it with moving images until the user desires to view the textual information again at which time the screen saver is removed.

U.S. Pat. No. 4,677,430 teaches a method for operating a display monitor to prevent burn-in of the screen. This patent discloses a method of imperceptibly moving displayed images by changing the temporal relationship between the information signal transmitted to the monitor and signals used to synchronize the scanning of the screen. The synchronizing signal is delayed with respect to the information signal and the delay is sequentially increased from a minimum delay to a maximum delay and then sequentially decreased back to the minimum delay over a relatively long period of time. The effect of this method is that the entire screen is shifted by a vertical displacement and/or a horizontal displacement.

U.S. Patent Application Publication Number US2001/0035874 discloses a method for reducing burn-in of a CRT that is used in closed circuit television (CCTV) applications. In these applications, text is typically overlaid on a video image, usually at the bottom of the screen. This patent application teaches a method of moving the overlaid text in a window by an amount in either the x or y-axes. This US2001/0035874 allows for textual information to be moved on the screen by inserting a blank space or moving a blank space in each character line by utilizing the character generator chip to provide blanked out portions. The method periodically changes the location of the textual information overlaid onto the video image by altering the information itself so that the information is continuously available, but does not remain in the same place for prolonged period of time thus avoiding burn-in of the textual information.

In certain applications, for example, in the transmission of music over cable television or satellite television networks, various content is typically displayed in conjunction with a broadcast music channel. In other applications, such as local display of advertising content on an in store display, or various other local broadcasts some content may remain stationary, resulting in screen burn-in. This content may include various components, such as, but not limited to, an image of the album cover, artist information, music trivia, channel title, various logos, advertising material, and various other content. Some of the content may remain relatively stationary on the screen with risk of causing burn-in. The methods developed thus far are each problematic or unusable in this application. For example, screen savers are not usable since they typically make the content temporarily unavailable or unreadable. The method utilized in U.S. Pat. No. 4,677,430 discussed above is not feasible for this application because it is undesirable and impractical to modify the synchronizing signal in order to cause shifting of the screen. The method of U.S. Patent Application Publication Number US2001/0035874 allows for textual information to be moved on the screen by inserting a blank space or moving a blank space in each character line by utilizing the character generator chip to provide blanked out portions. This method is not feasible for non-textual content that is displayed as an image in an area of the screen.

What is needed is a system and method for reducing screen burn-in of a user's display which is useful in applications where various content including but not limited to images, text, or graphics is displayed.

SUMMARY OF THE INVENTION

The invention provides a method and system for reducing uneven burn-in of a display during usage. A plurality of assets that may include text, graphics, and video are stored and then gathered. These assets are then assembled based on a template to form a video frame or “screen”, which is subsequently output to a display. Based upon a trigger, the assets are gathered again and reassembled in a second template to form a second video frame or “screen” wherein the assets are in positions on the screen, which are different from those of the first screen. The second screen is subsequently output to the display.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example with reference to the accompanying figures of which:

FIG. 1 is a diagrammatic view of a screen for display according to the present invention.

FIG. 2 is a second diagrammatic view of a screen for display according to the present invention.

FIG. 3 is a third diagrammatic view of a screen for display according to the present invention.

FIG. 4 is a block diagram of an exemplary system for generating screens for broadcast according the present invention.

FIG. 5 is a block diagram of a second exemplary system for generating screens according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The method for displaying content while reducing burn-in on a display will now be described with reference to FIGS. 1-3.

Referring first to FIG. 1, an exemplary screen 1 is shown containing various information and other content. Each of the items of content will hereinafter be referred to as assets. These assets may include but are not limited to textual information, motion picture video, graphics, control features such as buttons or pull down menus, promotional materials, or other control mechanisms. Referring first to FIG. 1, a plurality of assets is displayed on the screen 1. Those reasonably skilled in the art will appreciate that while certain assets will be described in these embodiments, other types of assets may be substituted. FIG. 1 shows a screen 1 which is displayed coincident with the transmission of a broadcast music channel. The screen 1 contains various assets including a logo 10, a song add button 12, a download button 14, a personalized channel choice button 16, a channel name 18, album art 20, title track label and artist information 22, promotional/advertising panels 24, 28 and a buy button 26. The logo and the album art assets 10, 20 contain graphical content while the channel name and title track label and artist assets 18, 22 contain primarily textual content but may also contain graphical content. The promotion/advertising panels 24, 28 may contain a combination of graphic and textual content and may alternatively contain motion picture video content. The assets described thus far namely 10, 18, 20, 22, 24, and 28 are primarily for the purpose of conveying information to the viewer either graphically, textually, or through video. The remaining assets namely the song add button 12, the download button 14, the personalized choice button 16, or the buy button 26 may each contain graphical and/or textual content for the purpose of allowing the user to make a selection or transfer control of the system to another sub-screen for various purposes. For example, these control buttons may be utilized to create a personalized music channel, to indicate music preferences of the user, to download a selected song, or to buy a selected album or track. It should be noted that each of the assets 12, 14, 16, 26 are arranged on the screen 1 in a given orientation and at a selected location, which is shown here as being bound by a border. It should be understood that in all cases the border is simply indicative of the location of the particular asset on the screen but that the border is not necessarily visible to the viewer.

In order to reduce screen burn-in, each of the assets may be shuffled around the screen 1 to create alternate orientations. For example, in FIG. 2, screen 2 is shown in which some of the assets are located in different positions from those shown in screen 1. For example, each of the assets has been relocated on the screen 2 except for the promotional/advertising panel 24, 28 that remains in the same location. If, for example, the content within the promotional/advertising panel 24, 28 changes over time, the need to move this asset around the screen in order to prevent burn-in is reduced. Therefore, in situations where content of an asset is changing within its location on a particular screen, the need to move the asset around the screen is either reduced or eliminated. Such changing may be in the form of changing graphics or video content.

FIG. 3 shows yet another screen in which all of the assets have been moved to alternate locations. The assets are moved to specified locations to prevent any stationary asset from remaining in one location on the screen for an extended period of time. The assets may be moved according to a specified movement arrangement, for example, from the arrangement of screen 1 to the arrangement of screen 2 then to the arrangement of screen 3 and subsequently to other arrangements thereafter returning to the arrangement of screen 1. The movement could alternatively be conducted according to a suitable random algorithm, which ensures that the resultant locations of each asset are such that there is no overlap of assets.

A time interval may be set for switching between screens 1, 2, and 3, or the change from screen to screen may be triggered by an event. For example, in an embodiment for transmitting a broadcast music channel, screen arrangements may change from screen 1 to screen 2 to screen 3 and other subsequent screens at the beginning of each new song being broadcast. Additionally, as mentioned above, it should be understood that assets may be selectively moved relative to each other or certain assets may remain fixed on the screen while others move. Those fixed assets are preferably ones in which the graphics, text, or video image within the asset changes at some interval. Those assets which are primarily textual or graphical and remain the same, for example the logo 10, should be moved to alternate locations from screen to screen in order to reduce screen burn-in in any one location.

An alternate embodiment of the method according to the present invention will be described with reference to FIG. 1. Instead of shuffling the assets as described above from screen 1 to screen 2 to screen 3 and so on, each asset may be incrementally moved along one or two axes on the screen as shown by the phantom lines in FIG. 1. For example, the logo 10 may be moved a given number of pixels along the y-axis a distance Δy and may also be moved a number of pixels along the x-axis a distance Δx. It should be understood that while the logo 10 is shown as being moved in two axes it may alternatively be moved in a single axis x or y. The movement in a single axis is best shown in the promotion/advertising panel 24, 28 which has been shifted along the x axis a small amount to the left in FIG. 1. The buy button 26 is also shown by way of example as being shifted a very small amount namely a few pixels in each of the x and y axes. It should be understood that while only three assets 10, 26, 24, 28 are shown here as being shifted or moved, each and every asset on the screen is capable of being similarly shifted either in a single axis or along both axes. Each asset may be shifted independent of the other and relative to each other without the need for shifting all assets together. In this way, assets can be shifted relative to each other incrementally along a predetermined pattern or randomly in such a way that their movement does not cause them to overlap. Additionally, the period between asset movements may be predetermined or random and the period may affect one or a plurality of assets at a given time.

An exemplary embodiment of a system for reducing burn-in of a display will now be described with reference to FIG. 4. An audio broadcast system 40 is designed for transmitting various music channel broadcasts over a network such as a cable television network or a satellite network for distribution to a plurality of subscribers. It should be understood, however, that while the system described here is utilized for the broadcast of audio channels, the system is adaptable for use in broadcasting other content as well.

In this exemplary embodiment, a data carousel subsystem 46 retrieves data from one or a plurality of data sources 42, 44. The first data source 42 may contain, for example, information to support the channel name asset 18 and may include a song identification database, which contains playlist information, which is programmed by genre or channel for a given type of music. The first data source 42 may be managed by and associated with a server, which allows the database to be updated and managed, and also facilitates communication with the data carousel subsystem 46.

The second data source 44 may include, for example, information to support the album art asset 20, the title and track label and artist asset 22, and information to support other assets. The second data source 44 may also be associated with and connected to a server or other computer for managing the database and/or facilitating communications with the data carousel subsystem 46. It should be understood that while two data sources are shown here, a single data source or a plurality of data sources may be connected to or in communication with the data carousel subsystem 46. The data sources 42, 44 may or may not be located in a single location and may or may not be co-located with the data carousel subsystem 46.

The data carousel subsystem 46 may be implemented utilizing a personal computer or a general-purpose computer having associated storage capabilities. The data carousel subsystem 46 receives data from data sources 42, 44 and may also receive data, which is downloadable from other data sources or entered directly into the data carousel subsystem 46 through user intervention. The data carousel subsystem 46 contains template information including a plurality of templates for the asset arrangements of screens 1, 2, and 3. As an alternative, the template information may be housed in one of the data sources 42, 44. The data carousel subsystem 46 is capable of managing/creating the templates, which may be coded utilizing HTML, XML or other suitable protocols for creating templates/screens having text and other assets such as those described above. Additionally, the data carousel subsystem 46 may store and execute suitable algorithms for moving selected assets such as the logo 10, the buy button 26, and the promotional/advertising panel 24, 28 as was shown and described above in the alternate methods with reference to FIGS. 1-3.

The broadcast playout system 50 is the mechanism by which fundamental programming content is played from recorded media. It is often based on commercially available broadcast automation hardware and software. The broadcast playout system 50 sends audio content, such as queued songs, to the audio encoder 49 and at a pre-determined time, sends a trigger to the data carousel subsystem 46 to initiate an associated data feed. The data carousel subsystem 46 generates a trigger to an MPEG encoder 47. In response to the trigger, the MPEG encoder 47 pulls template information, images, and text from the data carousel subsystem 46 and creates an MPEG video frame, having embedded assets such as screens 1, 2 or 3 which are associated with the currently queued song. This is accomplished by populating a given template or screen with current information/content from data sources 42, 44. It should be understood that this process may be executed for a plurality of channels simultaneously. The MPEG encoder 47 then creates an MPEG transport stream for all channels with the embedded MPEG video frames. The MPEG encoder 47 may be implemented utilizing a commercially available encoder or a general-purpose computer. Based upon a trigger from the broadcast playout system 50, a multiplexer 48 receives the MPEG transport stream from the MPEG encoder 47 and simultaneously receives an encoded audio feed from an audio encoder 49. The multiplexer 48 serves to combine the audio feed from the audio encoder 49 and the associated encoded MPEG transport stream from the MPEG encoder 47. The multiplexer 48 then feeds the multiplexed signal out for broadcast in the form of a video transport stream to the head end of a service provider, such as a cable television network or a satellite network provider as is well known in the art.

A second exemplary embodiment of an alternate system for reducing screen burn-in of a display will now be described with reference to FIG. 5. System 140 is designed for storing or locally transmitting various video and/or audio content according to the method described in reference to FIGS. 1-3 above.

In this second exemplary embodiment, a data carousel subsystem 146 retrieves data from one or a plurality of data sources 42, 44 as described in the embodiment of FIG. 4 above. It should be understood that the data sources 42, 44 may contain various assets not limited to those shown in the examples of FIGS. 1-3. The data carousel subsystem 146 may be implemented as part of a personal computer or general purpose computer having associated storage capabilities. Alternatively, the data carousel subsystem 146 may be implemented as a separate personal computer or general purpose computer having associated storage capabilities. The data carousel subsystem 146 contains similar template information as the data carousel subsystem 46 for creating various asset arrangements. It should be understood that the template information may be modified according to desired asset placement and replacement on the resultant screens. The data carousel subsystem 146 also has template management capabilities similar to the data carousel subsystem 46. Additionally, the data carousel subsystem 146 may store and execute suitable algorithms for moving selected assets as was shown and described above in the alternate methods with reference to FIGS. 1-3.

The image encoder 147 receives output from the data carousel subsystem 146 to create a video frame. The image encoder 147 may be implemented within a personal computer or general purpose computer or may alternatively be implemented as a separate piece of encoding equipment which is commercially available for generating encoded video frames.

An audio feed or audio encoder 149 supplies audio which is associated with the video frame output of the image encoder 147. It should be understood that the audio encoder 149 is an optional element in this system and may be removed in applications where only video without audio is desired. The audio encoder 149 may be implemented utilizing commercially available equipment or may be implemented as part of a personal or general purpose computer.

A multiplexer 148 serves to combine the audio feed/encoder output 149 with the image encoder output 147 to create a transport stream at its output. It should be understood that the audio encoder 149 and the image encoder 147 may be triggered or otherwise timed to send output to the multiplexer 148 simultaneously in order to match desired audio with desired image content. It should also be understood that the multiplexer 148 may be removed from the system 140 when the optional audio encoder 149 is not used. In this case, the image encoder 147 output could be fed directly into the storage/playout device 150 which will be described below.

The output of the multiplexer 148 is fed to a storage/playout device 150. The storage/playout device 150 may be implemented utilizing any display or transmission device which is capable of displaying or transmitting video images. Alternatively, in applications where playout is desired at a later time, the storage/playout device 150 may be implemented utilizing a recorder for creating or writing to any suitable storage medium such as DVD, CD ROM, hard disk, or any other suitable read only or rewritable storage medium. The storage/playout device 150 may be alternatively implemented utilizing portable memory devices according to PCMCIA or other suitable memory standards. The storage/playout device 150 could also be a direct playout device such as a display. The system 140 advantageously allows for utilizing the methods of the present invention for creating various stored content which when played back will reduce screen burn-in.

The elements of FIG. 5 may be incorporated within a personal or general purpose computer to reduce screen burn-in of a computer monitor by moving relatively still content on the computer display or monitor according to the methods of the present invention.

While this system 140 has been described in the context of generating a single frame or screen for display, it should be understood that this system 140 is utilized in executing the methods described above wherein the process is repeated such that assets are moved on the display according to the stored templates to reduce screen burn-in. It should also be understood that the system 140 is capable of simultaneously transmitting, playing out, or storing such content for later play back utilizing the methods disclosed above.

The system 40 advantageously reduces screen burn in by moving assets on the screen according to stored template information without modifying a transmitted TV signal or video transport stream. Assets are shifted on screen prior to output of the transport stream therefore eliminate the need to modify any signal at the display as required by the prior art.

The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. For example, it should be understood that this method and system may be applicable to broadcast systems as well as systems that display information from sources local to the display, including but not limited to video disc players, computers, etcetera. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents. 

1. A method of reducing screen burn-in comprising: assembling a plurality of separate and distinct assets to form a first screen; transmitting the first screen over a network to at least one receiving device configured to output the screen using a display device coupled to the receiving device; reassembling the assets to form a second screen having at least some of the assets occupy different positions than the positions they occupied in the first screen; transmitting the second screen over the network to the receiving device. 